Conversion adaptor apparatus and interchangeable lens system

ABSTRACT

A conversion adapter apparatus is provided that connects a camera body and an interchangeable lens. The conversion adapter apparatus includes a camera body side installation portion to receive a camera body, a lens side installation portion to receive an interchangeable lens, and a first communication contact group provided on the camera body side installation portion and connected to a communication contact group. The conversion adapter apparatus additionally includes a second communication contact group provided on the lens side installation portion and connected to the communication contact group and a conductive member that electrically connects the first communication contact group and the second communication contact group. A position of the first communication contact group around a camera optical axis and a position of the second communication contact group around the camera optical axis are different from each other.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a conversion adaptor apparatus and aninterchangeable lens system.

2. Description of the Related Art

In response to the desire to decrease the size and weight of digitalsingle reflex lens cameras, in recent years a new type of single lensreflex camera that differs from the conventional single lens reflexcamera has been proposed. The new type of single lens reflex camera isnot provided with a quick return mirror for guiding the imaging lightflux to a viewfinder, and the flange back is shorter than that of aconventional camera. The new type of interchangeable lenses having ashort flange back that is compatible with this new type of camera hasbeen proposed. However, these new type of interchangeable lenses cannoteasily handle a variety of photographic conditions because there are fewmodels. Therefore, there are cases in which it is desirable to use inthe new type of camera the conventional type of interchangeable lensesthat have already been introduced to the market and for which there areample models and quantities. Thus, a conversion adapter for connectingthe conventional type of interchangeable lenses with the new type ofcamera body is necessary. The functions required of this conversionadapter generally include matching the differing mounting profiles ofthe lenses and the camera body, matching the differing flange backs ofthe lenses and the camera body, and not hindering the communicationsystem between the lenses and the camera body.

In order to enable communication, which is a necessary function of aconversion adaptor, between the camera body and the interchangeablelens, communication contacts are provided on the conversion adaptor. Aconversion adaptor has been proposed in which the positions of thecommunication contacts connecting the camera body side and thecommunication contacts connecting the interchangeable lens side of theconversion adaptor are provided at positions around the camera opticalaxis that are identical. In this conversion adaptor, for example, aconducting member is provided that electrically connects twocorresponding connection contacts among the communication contacts thatconnect to the camera body side (camera body side communicationcontacts) and the communication contacts connected to theinterchangeable lens (lens side communication contacts).

Note that Japanese Patent Laid-Open No. H4-273671, discloses aconversion adaptor in an interchangeable lens system that controls afirst lens unit by communicating a control signal having a first signalprofile output from the camera body to a first lens unit. Thisconversion adaptor apparatus enables a second lens unit, which iscontrolled by control information having a second signal profile that isdifferent from the first signal profile, to connect to the camera body.

However, when the flange back of the camera body of the new type ofcamera described above and the flange back of the conventional type oflens are close, the conversion adaptor must be made thin. When theconversion adaptor is made thin, providing the camera body sidecommunication contacts and the lens side communication contacts of theconversion adaptor at positions around the camera optical axis that areidentical is difficult because they are spatially too close. Inaddition, in the case in which the camera body side communicationcontacts and the lens side communication contacts are close to theposition of the camera optical axis, the layout of the conducting memberthat provides electrical conduction between these communication contactsbecomes difficult. In addition, the assembly operability of the camerabody side communication contacts, the lens side communication contacts,and the conducting member deteriorates.

SUMMARY OF THE INVENTION

The conversion adapter apparatus of the embodiments of the presentinvention is a conversion adapter apparatus that connects a camera bodyand an interchangeable lens. The conversion adaptor apparatus includes acamera body side installation portion provided such that a camera bodycan be attached; a lens side installation portion provided such that aninterchangeable lens can be attached; a first communication contactgroup that is provided on the camera body side installation portion andconnects to the communication contact group on the camera body; a secondcommunication contact group that is provided on the lens sideinstallation portion and connects to the communication contact group ofthe interchangeable lens; and a conductive member that electricallyconnects the first communication contact group and the secondcommunication contact group. The position of the first communicationcontact group around the camera optical axis and the position of thesecond communication contact group around the camera optical axis aredifferent from each other.

Further features of the present invention will become apparent from thefollowing description of exemplary embodiments with reference to theattached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a drawing that shows an example of a schematic configurationof a camera overall that is provided with the conversion adaptor.

FIG. 2 is a drawing that shows the configuration of the conversionadaptor.

FIG. 3 is a drawing that shows an example of a schematic configurationof a camera overall that is provided with a conversion adaptor.

FIG. 4 is a drawing that shows the configuration of a conversionadaptor.

DESCRIPTION OF THE EMBODIMENTS

FIG. 1 is a drawing that shows an example of a schematic configurationof a camera overall that is provided with a conversion adaptor of afirst embodiment of the present invention. The camera that is shown inFIG. 1, for example, is a digital camera or a video camera that executesplanar image photography or three-dimensional image photography bycontrolling a plurality of photographic optical systems. The camerashown in FIG. 1 is provided with a camera body 10, an interchangeablelens 20, and a conversion adaptor 30 that connects the camera body 10and the interchangeable lens 20. The camera body 10 is a new type ofcamera having a flange back that is shorter than that of a conventionaltype of camera. The interchangeable lens 20 is attached to the camerabody 10 via the conversion adaptor 30. The respective standards for themounting portions of the camera body 10 and the interchangeable lens 20are different, and thus, they cannot be directly attached to each other.In addition, the flange backs of the camera body 10 and theinterchangeable lens 20 differ. The flange back of the camera body 10 isthe distance from a reference plane of the camera body 10 at which theinterchangeable lens 20 is installed to the imaging plane of the imagepickup element. In addition, the flange back of the interchangeable lens20 is the distance from a reference plane of the interchangeable lens 20at which the camera body 10 is installed to the focal point position.

The camera body 10 is provided with a camera body side mounting unit 11,a camera side communication contact group 12, a central processing unit(MPU: Micro Processing Unit) 100, and an image pickup element 400. Aquick return mirror and a dedicated focal point detecting unit and thelike are not provide in the camera body 10. The MPU 100 is a controlunit that carries out operational control of the camera, and executesvarious processes and instructions on the various elements of the camerasystem. The image pickup element 400 is an image pickup device thatconverts a subject image that has been imaged by a photographic opticalsystem to an electronic signal. In the present embodiment, a CMOS(Complementary Metal Oxide Semiconductor) sensor is used as the imagepickup element 400. Imaging devices having various configurations, suchas a CCD (Charge Coupled Device) type or a CID (Charge-injection Device)type, may be used as the image pickup element 400. After the electricalsignals of the image pickup elements 400 have undergone analog/digital(A/D) conversion, various known signal processes are carried out. Thecamera body side mounting unit 11 is provided at the end portion of thecamera body 10 on the subject side (interchangeable lens side). Amounting surface 11 a is provided at the end surface of the camera bodyside mounting unit 11 on the subject side. In addition, the camera sidecommunication contact group 12 is provided on the camera body mountingunit 11.

The interchangeable lens 20 is provided with a lens side mounting unit21, a lens side communication contact group 22, a photographic lens 200,a lens control circuit 201, an AF control circuit 202, a diaphragm drivecircuit 203, and a diaphragm 204. The photographic lens 200 is held soas to be movable in the direction of the optical axis by a lens drivingmeans such as a lens frame or an actuator (not illustrated) depending onthe distance to the subject being focused on. Note that although onephotographic lens 200 is illustrated for convenience in FIG. 1, thephotographic lens 200 actually includes a plurality of lens groups. Thelens control circuit 201 carries out communication with the MPU 100, andcarries out driving of the photographic lens 200 and the diaphragm 204in the interchangeable lens 20 via the AF control circuit 202 and thediaphragm drive circuit 203. The AF control circuit 202 is formed, forexample, by a stepping motor and carries out adjustments such that thefocus lens position in the photographic lens 200 is changed due to thecontrol of the lens control circuit 201 so as to align the focal pointof the photographic light flux on the image pickup element. Thediaphragm drive circuit 203 has, for example, an automatic iris, andchanges the diaphragm 204 according to the control of the lens controlcircuit 201 to obtain an optical diaphragm value. The lens side mountingunit 21 is provided at the end portion of the interchangeable lens 20 onthe camera operator side camera body side). A mounting surface 21 a isprovided at the end surface of the lens side mounting unit 21 of thecamera operator side. In addition, a lens side communication contactgroup 22 is provided on the lens side mounting unit 21.

The conversion adaptor 30 is the conversion adaptor apparatus of thepresent embodiment, and connects the camera body 10 and theinterchangeable lens 20. The conversion adaptor 30 is provided with acamera body side installation portion 31, a camera body sidecommunication contact group 32, a lens side installation portion 33, anda lens side communication contact group 34. In the present embodiment,the conversion adaptor 30 has a substantially cylindrical shape, but theshape of the conversion adaptor 30 is not limited to a cylindricalshape. The camera body side installation portion 31 is provided at oneend portion of the conversion adaptor 30, and is compatible with thestandards for the mounting portion of the cameral body 10. Specifically,the camera body side installation portion 31 is provided such that itcan be mounted on the camera body 10. The camera body side installationportion 31 includes a camera body side installation surface 31 a at theend surface of the camera body side. In addition, the camera body 10 canbe mounted in a configuration in which the mounting surface 11 a of thecamera body 10 and the camera body side installation surface 31 a are incontact. The camera body side communication contact group 32 is providedon the camera body side installation portion 31. The camera body sidecommunication contact group 32 is a first communication contact group,and when the camera body 10 has been installed on the camera body sideinstallation portion 31, it is in contact with the camera sidecommunication contact group 12 provided on the camera body side mountingportion 11.

The lens side installation portion 33 is installed at the end portionopposite to the camera body side installation portion 31, and iscompatible with the standard of the mounting portion of theinterchangeable lens 20. That is, the lens side installation portion 33can be mounted on the interchangeable lens 20. The lens sideinstallation portion 33 has a lens side installation surface 33 a at theend portion of the interchangeable lens side. In addition, theinterchangeable lens 20 is detachably installed in a configuration inwhich the mounting surface 21 a of the interchangeable lens 20 and thelens side installation surface 33 a are in contact. The lens sidecommunication contact group 34 is provided on the lens side installationportion 33. The lens side communication contact group 34 is a secondcommunication contact group, and when the interchangeable lens 20 isinstalled on the lens side installation portion 33, it is in contactwith the lens side communication contact group 22 provided on the lensside mounting portion 21.

In addition, in the present embodiment, the camera body sidecommunication contact group 32 and the lens side communication contactgroup 34 of the conversion adaptor 30 are provided at positions opposedto each other such that the optical axis (camera optical axis) isinterposed therebetween. The camera body side communication contactgroup 32 and the lens side communication contact group 34 areelectrically connected by a conducting member 301, such as a flexibleprinted substrate or a lead wire or the like. Thereby, the MPU 100 cancarry out a variety of communication with the lens control circuit 201inside the interchangeable lens 20 via the camera side communicationcontact group 12, the camera body side communication contact group 32,the conducting member 301, and the lens side communication contactgroups 34 and 22. For example, the MPU 100 can carry out lens attachmentand detachment communication, lens data communication, and lens drivecommunication and the like with the lens control circuit 201.

Here, a symbol “C” shown in FIG. 1 denotes the thickness of theconversion adaptor 30. The thickness is a distance in the direction ofthe optical axis from the camera body side installation surface 31 a tothe lens side installation surface 33 a. As shown in FIG. 1, when theflange back of the camera body 10 is denoted by “A” and the flange backof the interchangeable lens 20 is denoted by “B”, then the relationshipC=B−A holds. Specifically, the flange back of the camera body 10 isshorter than the flange back of the interchangeable lens 20, and thethickness of the conversion adaptor corresponds to the differencebetween the flange back of the camera body 10 and the flange back of theinterchangeable lens 20. In the present embodiment, by using aconversion adaptor 30 having a thickness that is the difference Cbetween the flange back A of the camera body 10 and the flange back ofthe interchangeable lens 20, i.e., C=B−A, both of the flange backs canbe aligned (matched).

The interchangeable lens system of the present embodiment can berealized as an interchangeable lens system provided with the conversionadaptor of the present embodiment described above with reference toFIG. 1. According to the conversion adaptor and the interchangeable lenssystem of the present embodiment, the user can attach an interchangeablelens 20 to the camera body 10 and photograph normally without beingaffected by differences in the mounting standards and the flange backstandards.

FIG. 2 is a drawing that shows the configuration of the conversionadaptor shown in FIG. 1. A symbol “A” in FIG. 2 denotes a drawing inwhich the conversion adaptor 30 is viewed from the interchangeable lensside, and principally shows the lens side installation portion 33 of theconversion adaptor 30. A symbol “B” in FIG. 2 denotes a drawing in whichthe conversion adaptor 30 is viewed from the side. A symbol “C” in FIG.2 denotes a drawing in which the conversion adaptor 30 is viewed fromthe camera body side, and principally shows the camera body sideinstallation portion 31 of the conversion adaptor 30. As shown in FIG.2, a catch portion 35, which is a convexity, is provided at threelocations at the outside in a radial direction on the camera body sideinstallation portion 31. By rotating the conversion adaptor 30 to theright when viewed from the interchangeable lens side and the catchportions 35 are hooked on the catch portions of the mounting portion ofthe camera body (not illustrated), the attachment to the camera body 10becomes possible. In contrast, as shown in FIG. 2, catch portions 36,which are convexities, are provided at three locations on the inside ofthe lens side installation portion 33 in the radial direction. Byrotating the interchangeable lens 20 to the right when viewed from theinterchangeable lens side and catching the catch portions of themounting portion of the interchangeable lens (not illustrated) on thecatch portions 36, the installation of the interchangeable lens 20becomes possible.

The size of the camera body side installation portion 31 is small incomparison to the size of the lens side installation portion 33. This isbecause the mounting standards for the camera body side mounting portion11 and the lens side mounting portion 21 are different, and the camerabody side mounting portion 11 is smaller. The camera body sidecommunication contact group 32 is disposed on the camera body sideinstallation portion 31 above the optical axis (above the optical axiswhen the camera is in the normal position). The camera body sidecommunication contact group 32 includes communication contacts 320 to329, which are substantially rectangular flat contacts. Thecommunication contacts 320 to 329 correspond to the communicationcontacts that are included in the camera body side communication contactgroup 12 on the camera body 10.

The roles of the communication contacts included in the camera body sidecommunication contact group 32 are indicated herein. The communicationcontact 320 is a lens drive power source communication contact. Thecommunication contact 321 is a lens drive GND contact. Communicationcontacts 322 to 326 are signal contacts. Specifically, the communicationcontact 322 is a lens control circuit power source contact, andcommunication contact 323 is a signal contact for signals from thecamera to the lens. The communication contact 324 is a signal contactfor signals from the lens to the camera, the communication contact 325is a contact for synchronizing the communication clocks of the cameraand the lens, and the communication contact 326 is the lens controlcircuit GND contact. Communication contacts 327 to 329 are communicationcontacts corresponding to mounting standards for a new type of camera.Communication contacts 327 to 329 are second drive power source contactsthat differ from the above described communication contact 320 and 321,and are used when carrying out driving that differs from normal lensdriving. For example, these are used when carrying out, for example, anoperation in which the focal speed is slowed by slowly moving the focuslenses inside the photographic lenses 200 or an operation in which thefocal speed is hastened by quickly moving the focus lenses.Communication contact 327 is a second lens drive power source contact,and communication contact 328 is a contact that confirms whether or nota lens that can perform the special operation described above has beencorrectly attached. Communication contact 329 is the second lens drivingGND contact.

In contrast, as shown in FIG. 2, on the lens side installation portion33, a lens side communication contact group 34 is provided at a positionopposed to the camera body side communication contact group 32 (belowthe optical axis when the camera is in the normal position) such thatthe optical axis is interposed therebetween. Specifically, the positionof the camera body side communication contact group 32 around theoptical axis of the camera and the position of the lens sidecommunication contact group 34 around the camera optical axis differfrom each other. Because the communication contact group 22 of theinterchangeable lens 20 is disposed below the optical axis when thecamera is in the normal position, the user can attach interchangeablelens 20 to the conversion adaptor 30 in the same manner as theinterchangeable lens attachment operation on a normal camera.

The lens side communication contact group 34 is substantiallycylindrical, and is provided with communication contacts 340 to 347,which have a circular contact surface. Communication contacts 340 to 347can Move in the direction of the optical axis, and are supported byflexible members such as springs therein. Communication contacts 340 to347 correspond to the communication contacts included in thecommunication contact group 22 of the lens. When external pressure isapplied from the lens side installation portion 33 toward the camerabody side installation portion 31, communication contacts 340 to 347move in response to the applied external pressure. When no load isapplied, they return to their original position. Therefore, when aninterchangeable lens 20 is attached, the communication contacts 340 to347 can be brought into contact with corresponding communicationcontacts included in the lens side communication contact group 22 by aconstant reaction force. As a result, disconnections between contactscan be prevented, and stable communication can be carried out. Note thatif communication contacts 340 to 347 are provided so as to be in contactwith the communication contacts of the interchangeable lens 20 while theinterchangeable lens 20 is attached to the conversion adaptor 30 by aconstant reaction force, the direction of movement of the communicationcontacts 340 to 347 may be in a radial direction. In addition, thecommunication contacts 340 to 347 may be immovable.

The roles of communication contacts 340 to 347 are indicated herein.Communication contacts 340 to 342 are drive power source contacts.Specifically, communication contact 340 is a lens drive power sourcecontact and communication contact 341 is a contact for confirming thepresence or absence of lens attachment. Communication contact 342 is alens drive GND contact. Communication contacts 343 to 347 are signalcontacts. Specifically, communication contact 343 is a lens controlcircuit power source contact, communication contact 344 is a signalcontact for signals from the camera to the lens, and communicationcontact 345 is a signal contact for signals from the lens to the camera.In addition, communication contact 346 is a contact for synchronizingthe communication clocks of the camera and the lens, and communicationcontact 347 is a lens control circuit GND contact.

The communication contacts (first communication contacts) included inthe camera body side communication contact group 32 and thecommunication contacts (second communication contacts) included in thelens side communication contact group 34 and corresponding to the firstcommunication contacts are electrically connected by the conductingmember 301. For example, the communication contact 320 is connected tothe communication contact 340, which is the corresponding communicationcontact, and communication contact 321 is connected to communicationcontacts 341 and 342, which are the corresponding communicationcontacts. In addition, communication contact 322 is connected tocommunication contact 343, which is the corresponding communicationcontact, and communication contact 323 is connected to communicationcontact 344, which is the corresponding communication contact. Inaddition, communication contact 324 is connected to communicationcontact 345, which is the corresponding communication contact, andcommunication contact 325 is connected to the communication contact 346,which is the corresponding communication contact. In addition,communication contact 326 is connected to communication contact 347,which is the corresponding communication contact. Note that thecommunication contacts corresponding to communication contact 327 and329 are not provided on the lens side installation portion 33.

Here, assume the case in which the camera body side communicationcontact group 32 and the lens side communication contact group 34 aredisposed such that their positions around their camera optical axes areidentical (for example, both contact groups are disposed at positionbelow the optical axis when the camera is in the normal position). Inthis case, because the conversion adaptor 30 is thin and the layoutvolume of the lens side communication contact group 34 in the directionof the optical axis is large, the camera body side communication contactgroup 32 and the lens side communication contact group 34 are close. Asa result, the disposition layout of the camera body side communicationcontact group 32 and the lens side communication contact group 34becomes difficult. In addition, even if we suppose that the camera bodyside communication contact group 32 and the lens side communicationcontact group 34 can be laid out, the conducting member 301 thatconnects the camera body side communication contact group 32 and thelens side communication contact group 34 becomes short. As a result, thedisposition of the communication contact groups, the disposition of theconducting member 301, and the assembly operability of the communicationcontact groups and the conducting member 301 become unfavorable.

In contrast, in the conversion adaptor of the present embodiment, theposition of the camera body side communication contact group 32 aroundthe camera optical axis and the position of the lens side communicationcontact group 34 around the camera optical axis are disposed so as to bedifferent from each other. Specifically, in the conversion adaptor ofthe present embodiment, the camera body side communication contact group32 and the lens side communication contact group 34 are disposed so asto oppose each other with the optical axis interposed therebetween.Therefore, according to the conversion adaptor of the presentembodiment, an interval having a prescribed length can be establishedbetween the camera body side communication contact group 32 and the lensside communication contact group 34. As a result, the layout of thecamera body side communication contact group 32 and the lens sidecommunication contact group 34 can be improved. In addition, the layoutof the conducting member 301 that provides conduction between the camerabody side communication contact group 32 and the lens side communicationcontact group 34, and the assembly operability of the camera body sidecommunication contact group 32, the lens side communication contactgroup 34, and the conducting member 301 can be improved.

Note that in the present embodiment, the communication contacts 327through 329 are second drive power source contact points, butcommunication contacts 327 to 329 may be additional signal contactpoints to enable communicating more information than is conventionallycommunicated between the camera body 10 and the conversion adaptor 20.In addition, the number of the second drive power source contact pointsand the additional signal contacts described above may be larger orsmaller than the number of communication contacts 327 to 329 shown inFIG. 2. In addition, the disposition locations for the communicationcontacts 327 to 329 may be, for example, between the power sourcecontact points and the signal contact points. In addition, the camerabody side communication contact group 32 may have a structure in whichthe communication contacts 327 to 329 are not provided.

In the present embodiment, the camera body side communication contactgroup 32 of the conversion adaptor 30 is disposed above the optical axiswhen the camera is in the normal position and the lens sidecommunication contact group 34 is disposed below the optical axis whenthe camera is in the normal position, and thus, there are the followingmerits for the camera body side. Specifically, in a new type camera, theelectronic viewfinder, the display member, and the operation member andthe like disposed so as to be concentrated above the mount, and theelectronic mounting system also is disposed so as to be concentratedabove the mount. Therefore, the camera body side communication contactgroup 32 is disposed above the optical axis when the camera is in thenormal position, and thereby, the layout efficiency of the electronicmounting system is improved.

FIG. 3 is a drawing that shows an example of an overall schematicconfiguration of the camera that is provided with a conversion adaptorapparatus of a second embodiment of the present invention. Among theconstituent portions provided by the camera shown in FIG. 3, theconstituent portions provided by the camera shown in FIG. 1 denoted byidentical reference numerals have a function that is identical to theconstituent portions that are provided by the camera shown in FIG. 1.The camera shown in FIG. 3 is provided with a camera body 10, aninterchangeable lens 20, and a conversion adaptor 40 that connects thecamera body 10 and the interchangeable lens.

The point of difference between the conversion adaptor 40 and theconversion adaptor 30 shown in FIG. 1 is that the camera body sidecommunication contact group 42 of the camera body side installationportion 41 is disposed on the right side of the optical axis, andotherwise, the configuration and functions are identical to theconfiguration and function provided by the conversion adaptor 30.Specifically, the camera body side installation portion 41 provided bythe conversion adaptor 40 has a function that is identical to thefunction of the camera body side installation portion 31 that is shownin FIG. 1. In addition, the camera body side communication contact group42 has a function that is identical to the function of the camera bodyside communication contact group 32 that is shown in FIG. 1. Inaddition, the lens side installation portion 43 has a function that isidentical to the function of the lens side installation portion 33 thatis shown in FIG. 1. In addition, the lens side communication contactgroup 44 has a function that is identical to the function of the lensside communication contact group 34 that is shown in FIG. 1. The camerabody side installation portion 41 has camera body side installationsurface 41 a on the end surface on the camera body side. The camera bodyside installation surface 41 a has a function that is identical to thefunction of the camera body side installation surface 31 a that is shownin FIG. 1. The lens side installation portion 33 has a lens sideinstallation surface 43 a on the end surface on the interchangeable lensside. The lens side installation surface 43 a has a function that isidentical to the function of the lens side installation surface 33 athat is shown in FIG. 1. In addition, the camera body side communicationcontact group 42 and the lens side communication contact group 44 areelectrically connected via the conducting member 401, which has afunction that is identical to that of the conducting member 301 that isshown in FIG. 1. The interchangeable lens system of the presentembodiment can be realized as an interchangeable lens system providedwith the conversion adaptor 40 that is shown in FIG. 3.

FIG. 4 is a drawing that shows the configuration of the conversionadaptor shown in FIG. 3. A symbol “A” in FIG. 4 denotes a drawing inwhich the conversion adaptor 40 is viewed from the interchangeable lensside. A symbol “B” in FIG. 4 denotes a drawing in which the conversionadaptor 40 is viewed from the side. A symbol “C” in FIG. 4 denotes adrawing in which the conversion adaptor 40 is viewed from the camerabody side. The function of the communication contacts (communicationcontacts 420 to 429) provided by the camera body side communicationcontact group 42 that is shown in FIG. 4 is identical to the function ofthe communication contacts (communication contacts 320 to 329) providedby the camera body side communication contact group 32 that is shown inFIG. 2. In addition, the function of the communication contacts(communication contacts 440 to 447) provided by the lens sidecommunication contact group 44 that is shown in FIG. 4 is identical tothe function of the communication contacts (communication contacts 340to 347) provided by the lens side communication contact group 34 that isshown in FIG. 2. In addition, the catch portion 46 that is shown in FIG.4 has a function that is identical to the catch portion 36 that is shownin FIG. 2, and the catch portion 45 that is shown in FIG. 4 has afunction that is identical to that of the catch portion 45 that is shownin FIG. 2. Note that the camera body side communication contact group 12provided by the camera body 10 is disposed on the right side of theoptical axis, when the camera is in the normal position, such that thecamera body 10 is in contact with the camera body side communicationcontact group 42 when the camera body 10 has an interchangeable lens 40attached thereto.

In the second embodiment of the present invention, as shown in FIG. 4,the camera body side communication contact group 42 of the conversionadaptor 40 is disposed on the right side of the optical axis (the rightside of the optical axis when viewed from the photographer's side whilethe camera is in the normal position). In addition, as shown in FIG. 4,the lens side communication contact group 44 of the conversion adaptor40 is disposed below the optical axis (below the optical axis while thecamera is in the normal position). Specifically, the camera body sidecommunication contact group 42 and the lens side communication contactgroup 44 are provided at positions separated by 90 degrees around theoptical axis of the camera (in the example shown in FIG. 4, a positionoffset by an approximately ¼ rotation in the peripheral direction of acircle centered on the optical axis). Therefore, according to theconversion adaptor 40, an interval of a predetermined distance can beestablished between the camera body side communication contact group 42and the lens side communication contact group 44. As a result, thelayout of the camera body side communication contact group 42 and thelens side communication contact group 44 can be improved. In addition,the layout of the conducting member 401 that provides electricalconduction between the camera body side communication contact group 42and the lens side communication contact group 44, and the assemblyoperability for the camera body side communication contact group 42, thelens side communication contact group 44, and the conducting member 401can be improved.

In addition, there are the following merits in the case in which thecamera body 10 is one that is compatible with a new type of camera inwhich the battery, which is the power source, is disposed inside a gripthat is on the right of the optical axis. Specifically, in the secondembodiment of the present invention, because the camera body sidecommunication contact group 12 of the camera body 10 is disposed to theright of the optical axis, the camera body side communication contactgroup 12 is disposed at a position in proximity to the power source, andthe layout efficiency of the electrical mounting system is therebyimproved.

The present invention has been described in detail based on preferredembodiments thereof, but the present invention is not limited byspecific embodiments, and the present invention includes various formswithin a range that does not depart from the spirit of the presentinvention. Portions of the embodiments described above may be suitablycombined. For example, the position at which the space between thecamera body side communication contact group and the lens sidecommunication contact group that are provided by the conversion adaptorof the present invention may be a position at which an interval having apredetermined distance between the camera body side communicationcontact group and the lens side communication contact group can beestablished. Specifically, the camera body side communication contactgroup and the lens side communication contact group provided by theconversion adaptor apparatus may be provided at a position separated bya freely chosen number of degrees of separation around the optical axisof the camera.

In addition, in the present embodiment, an example is provided in whichthe mounting standard for the camera body and the mounting standard forthe interchangeable lens differ, including the size of the mount, butthe sizes of both mounts may be identical. In this case, only the sizeof the camera body side installation portion and the lens sideinstallation portion of the conversion adaptor are identical, and thisdoes not depart from the spirit of the invention with respect to thedisposition of the communication contact groups.

According to the conversion adaptor apparatus of the present inventionexplained above, the attachment of an interchangeable lens to a camerabody having a different flange back becomes possible, and at the sametime, the layout of the communication contacts on the camera body sideand the communication contacts on the lens side of the conversionadaptor can be improved. In addition, according to the conversionadaptor apparatus of the present invention, the layout of the conductingmember that provides electrical conduction between the correspondingcommunication contacts provided by the conversion adaptor apparatus, andthe assembly operability for the communication contacts and theconducting member can be improved.

Aspects of the present invention can also be realized by a computer of asystem or apparatus (or devices such as a CPU or MPU) that reads out andexecutes a program recorded on a memory device to perform the functionsof the above-described embodiments, and by a method, the steps of whichare performed by a computer of a system or apparatus by, for example,reading out and executing a program recorded on a memory device toperform the functions of the above-described embodiments. For thispurpose, the program is provided to the computer for example via anetwork or from a recording medium of various types serving as thememory device (e.g., computer-readable medium).

While the present invention has been described with reference toexemplary embodiments, it is to be understood that the invention is notlimited to the disclosed exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all such modifications and equivalent structures andfunctions.

This application claims the benefit of Japanese Patent Application No.2009-202250 filed Sep. 2, 2009 which is hereby incorporated by referenceherein in its entirety.

What is claimed is:
 1. A conversion adapter apparatus that connects acamera body and an interchangeable lens, comprising: a camera body sideinstallation portion provided such that a camera body can be attached; alens side installation portion provided such that an interchangeablelens can be attached; a first communication contact group that isprovided on the camera body side installation portion and connects tothe communication contact group of the camera body; a secondcommunication contact group that is provided on the lens sideinstallation portion and connects to the communication contact group ofthe interchangeable lens; and a conductive member that electricallyconnects the first communication contact group and the secondcommunication contact group; wherein the position of the firstcommunication contact group around the camera optical axis and theposition of the second communication contact group around the cameraoptical axis are different from each other.
 2. The conversion adaptorapparatus according to claim 1, wherein the first communication contactgroup and the second communication contact group are provided atopposing positions so that the camera optical axis is interposedtherebetween.
 3. The conversion adaptor according to claim 2, whereinthe first communication contact group is provided above the cameraoptical axis when the camera is in the normal position.
 4. A conversionadaptor apparatus according to claim 1, wherein the first communicationcontact group and the second communication contact group are provided atpositions offset by 90 degrees around the camera optical axis.
 5. Aconversion adaptor apparatus according to claim 4, wherein thecommunication contact group of the camera body that is in contact withthe first communication contact group is provided at a position inproximity to the power source of the camera.
 6. A conversion adaptorapparatus according to claim 1, wherein the second communication contactgroup is provided so as to be in contact with the communication contactsof the interchangeable lens due to a predetermined reaction force whenthe interchangeable lens is attached to the conversion adaptorapparatus.
 7. A conversion adaptor apparatus according to claim 1,wherein the flange back of the camera body is shorter than the flangeback of the interchangeable lens, and the thickness of the conversionadaptor apparatus is the difference between the flange back of thecamera body and the flange back of the interchangeable lens.
 8. Aninterchangeable lens system provided with a conversion adaptor apparatusthat connects a camera body and an interchangeable lens, wherein theconversion adaptor apparatus comprises: a camera body side installationportion provided such that a camera body can be attached; a lens sideinstallation portion provided such that an interchangeable lens can beattached; a first communication contact group that is provided on thecamera body side installation portion and connects to the communicationcontact group of the camera body; a second communication contact groupthat is provided on the lens side installation portion and connects tothe communication contact group of the interchangeable lens; and aconductive member that electrically connects the first communicationcontact group and the second communication contact group; wherein theposition of the first communication contact group around the cameraoptical axis and the position of the second communication contact grouparound the camera optical axis are different from each other.